1. Field of the Invention
The present invention relates to power supplies and more particularly relates to a rectifier power supply having an improved inrush circuit that limits cold start inrush currents while maximizing efficiency by substantially reducing steady state losses.
2. Description of the Prior Art
Modem electrical equipment marketed internationally must include either an internal or external power supply that is able to operate with any given countries adopted line voltage standard without special switches or user intervention. In this regard, the power supply must operate with voltages that range between about 85 VAC.sub.rms and about 264 VAC.sub.rms.
Most, if not all, conventional power supplies that meet this need include in-line current limiting circuitry to protect the energized equipment from unwanted and undesired transient voltage and current surges that typically occur at power up times. Such in-line current limiting circuitry is generally expensive to manufacture, and is inefficient due to the dissipation of large amounts of power through the high wattage rated current limiting devices associated with such circuitry.
Therefore it would be highly desirable to have a new and improved power supply that is highly efficient and that operates without user intervention with the various world standard AC line voltages. Such a new and improved power supply should also be relatively inexpensive to manufacture, and should at least meet or exceed the International Electrotechnical Commission (IEC) adopted standards relative to limiting input current harmonics, and reducing flicker.